Parsing Efficiency, Computational Complexity, and the Evaluation of Grammatical Theories

Investigated are the theoretical relationship between linguistic theories of generative grammar & the efficiency of parsing algorithms as traditionally analyzed in computer science. It is argued that the mathematically defined hierarchy of languages (finite state, context-free, context-sensitive) usually studied is unilluminating from the viewpoint of linguistic theory. This is because these mathematically defined classes do not necessarily correspond to the natural classes of language defined on grounds of linguistic theory or even efficient parsing. In particular, the use of asymptotic complexity analyses to argue that natural language must be context-free is found to be misleading, & not necessarily relevant in a realistic biological or linguistic context. 3 Figures. AA